Triclosan

Triclosan, also known as 2,4,4’-Trichloro-2’-hydroxyphenyl ether, is a phenolic diphenol ether, used for over 30 years as a preservative, antibacterial, and antifungal.[1] It was patented and used in medical supplies in 1964 and by 1987 was being used in consumer products.[2]

There have been numerous health concerns linked to triclosan. In December 2013, the U.S. Food and Drug Administration (FDA) issued a proposed rule "to require manufacturers of antibacterial hand soaps and body washes to demonstrate that their products are safe for long-term daily use and more effective than plain soap and water in preventing illness and the spread of certain infections." The proposed rule explicitly references the commonly used triclosan and the related triclocarban (used in bar soaps), because they "could pose health risks, such as bacterial resistance or hormonal effects."[3] Specifically, the proposed rule cites concern over new findings in animal studies of "a negative effect on both cardiac and skeletal muscle function as a result of a single triclosan treatment"; another study finding that "rats that were exposed to a high dose (3,000 ppm) of triclosan in utero showed lower neonatal survival and lower mean body weights compared to untreated controls"; studies finding "a reduction or absence of spermatozoa, abnormal spermatogenic cells, and partial depletion of one or more generations of germ cells in male testes" in hamsters exposed to a high dose of triclosan; and potential "cross-resistance between antiseptic active ingredients and antibiotics."[4]

The American Medical Association released a statement in 2012 encouraging "the preferential use of plain soap and water or alcohol-based hand sanitizers in health-care settings."[5] In April 2010, after prompting from Representative Edward Markey (D-MA), the FDA and EPA announced they would reconsider the safety and usefulness of triclosan.[6] With widespread use of triclosan in personal care products, the Natural Resources Defense Council has called on the U.S. FDA to ban the chemical. In a press release, NRDC Senior Scientist Dr. Sarah Janssen said, "With no proven benefit and many red flags raised for harmful health impacts, the use of these so-called anti-microbials is an unnecessary and stupid use of toxic chemicals."[7] On July 27, 2010, NRDC filed a lawsuit against the FDA for its failure to finalize a ban on both triclocarban and triclosan, which was first initiated in 1978.[8] The lawsuit covers liquid and bar soaps and body washes. The FDA's December 2013 proposed rule was issued as a result of a settlement between NRDC and the agency in November 2013.[9][10]

With its common household use, triclosan makes its way into the wastewater stream and frequently turns up in sewage sludge.

Uses

Triclosan is found in clothing, kitchenware, furniture, toys, medical devices, antibacterial soaps and body washes, deodorants, acne medications, mouthwashes, toothpastes, wound disinfection solutions, and cosmetics.[11][12] Triclosan is found in 75 percent of liquid hand soaps.[13] However, an advisory panel to the FDA found in 2005 that there is no evidence that antibacterial soaps are more effective than regular soap and water.[14] In April 2013, the FDA amended its page on triclosan to say the following: "At this time, the agency does not have evidence that triclosan in antibacterial soaps and body washes provides any benefit over washing with regular soap and water."[15][16][17]

Triclosan as a Pollutant

Triclosan enters the environment either via effluent released from wastewater treatment plants or in sewage sludge applied to land.[19] In 1999-2000, triclosan was found in 57.6% of 139 U.S. streams sampled in 30 states.[20] A recent study found that soybeans grown in sewage sludge took up triclosan.[21] Increasingly, triclosan is also found in the bodies of Americans.[22] When triclosan breaks down, it can form small amounts of 2,8-dichlorodibenzo-p-dioxin.[23]

In Sewage Sludge

2010 Tests of San Francisco Sewage Sludge Find PBDEs, Triclosan

On August 10, 2010, the Food Rights Network announced in a news release that "Independent tests of sewage sludge-derived compost from the Synagro CVC plant -- distributed free to gardeners since 2007 by the San Francisco Public Utilities Commission in their "organic biosolids compost" giveaway program -- have found appreciable concentrations of contaminants with endocrine-disruptive properties. The independent tests were conducted for the Food Rights Networkby Dr. Robert C. Hale of the Virginia Institute of Marine Sciences."

In an August 6, 2010, letter reporting on his findings to the Food Rights Network Robert Hale wrote: "A sewage sludge-derived compost from the Synagro CVC plant, distributed by the San Francisco Public Utilities Commission in their "compost give away" program, was analyzed for synthetic pollutants. Several classes of emerging contaminants with endocrine disruptive properties were detected in appreciable concentrations, including polybrominated diphenyl ether (PBDE) flame retardants, nonylphenols (NPs) detergent breakdown products and the antibacterial agent triclosan." PDFs are attached here of the letter and the data:[27][28][29][30]

Plant Uptake of Triclosan

A study by researchers at the University of Toledo examined the uptake of three pharmaceuticals, carbamazepine, diphenhydramine (Benadryl), and fluoxetine (Prozac), and two personal care products, triclosan and triclocarban, by soybean plants.[31] The plants were grown in "treatments simulating biosolids application and wastewater irrigation." The plants were then examined after growing for 60 and 110 days. The plants concentrated carbamazepine, triclosan, and triclocarban in their roots but the three chemicals were found translocated in the above ground parts of the plants, including the beans. Concentrations were higher in the plants grown in simulated biosolids, or sewage sludge.

Human Exposure and Health Effects

Humans are exposed to triclosan through the many consumer products containing it and possibly by ingesting food grown in fields fertilized with contaminated sewage sludge[32][33] After use of toothpaste containing triclosan, triclosan can remain present in human saliva for several hours. Triclosan can also be absorbed by the skin into the blood stream. In studies, it is excreted, primarily as unchanged triclosan, over several days in the feces and urine.[34] The CDC found a significant increase in urinary triclosan levels between studies complete in 2003-04 and 2005-06.[35] The mean level of urinary triclosan increased from 13.0 micrograms per liter in 2003-04 to 18.5 micrograms per liter in 2005-06. This represents a 42.3% increase. Measured as micrograms per gram of creatinine, mean urinary triclosan increased from 12.7 in 2003-04 to 18.0 in 2005-06, a 41.7 percent increase.

Triclosan is a suspected endocrine disruptor. In 2009, the Endocrine Society released a statement advising pregnant women and small children to avoid triclosan if possible, as developing organs are at a higher risk to be effected by the chemical. The society commented, "even if some health effects are not fully proven scientifically, taking precautions is wise."[36] In 2012, Johnson & Johnson stated the removal of triclosan from their beauty and baby products to address the growing concerns of clients.[37]

In animal tests, triclosan interferes with thyroid hormone (serum total thyroxine), which is critical for normal growth and brain development, as well as male and female sex hormones, which are necessary for the normal growth and function of the reproductive system.[38][39] One study found that triclosan decreased sperm count, damaged the male reproductive system, and disrupted male hormone production in rats.[40] Scientists fear that it may have the same effects on humans because humans have similar hormone systems as animals.[41] Additionally, is concern that overuse of triclosan promotes antibiotic resistance among bacterial.[42]